Perhaps you should try some spelling variations:
chau tre » chay tren, chau tho, cho tre
hanh lai » hanh lam, hanh tai, thanh lap
hoc sach » hoc sinh, hoc cac, hoc anh
ly nang » ky nang, ly hang, ly vang
hieu ve » hieu va, hieu van
cam duc » cam xuc, cao duc, nam duoc
va hanh » van hanh, va thanh, va danh
vu sach » vu bach, su sach, vu khach
nang o » nang co, nang ho, nang ro
o hoc » co hoc, mo hoc, so hoc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (hoc sach)) ly nang o hoc. hieu ve ((cam duc) OR (pham duc)) va hanh lai chau tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (hoc sach)) ly nang o hoc. hieu ve ((cam duc) OR (pham duc)) va hanh lai chau tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (hoc sach)) ly nang o hoc. hieu ve ((cam duc) OR (pham duc)) va hanh lai chau tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (hoc sach)) ly nang o hoc. hieu ve ((cam duc) OR (pham duc)) va hanh lai chau tre*.